- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Wed, 10 Jul 2013 08:40:39 -0700
- To: 'RDF WG' <public-rdf-wg@w3.org>
An RDF triple encodes a statement—a simple logical expression, or claim about the world. An RDF graph is the conjunction (logical AND) of its triples. The precise details of this meaning of RDF triples and graphs are the subject of the RDF Semantics specification [RDF-MT], which yields the following relationships between RDF graphs: Entailment An RDF graph A entails another RDF graph B if every possible arrangement of the world that makes A true also makes B true. When A entails B, if the truth of A is presumed or demonstrated then the truth of B is established. Equivalence Two RDF graphs A and B are equivalent if they make the same claim about the world. A is equivalent to B if and only if A entails B and B entails A. Inconsistency An RDF graph is inconsistent if it contains an internal contradiction. There is no possible arrangement of the world that would make the expression true. An entailment regime [RDF-MT] is a specification that defines precise conditions that make these relationships hold. RDF itself recognizes only some basic cases of entailment, equivalence and inconsistency. Other specifications, such as RDF Schema [RDF-SCHEMA] and OWL 2 [OWL2-OVERVIEW], add more powerful entailment regimes, as do some domain-specific vocabularies. This specification does not constrain how implementations use the logical relationships defined by entailment regimes. Implementations may or may not detect inconsistencies, and may make all, some or no entailed information available to users. peter
Received on Wednesday, 10 July 2013 15:41:09 UTC